1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Linux driver for digital TV devices equipped with B2C2 FlexcopII(b)/III
4  * flexcop-eeprom.c - eeprom access methods (currently only MAC address reading)
5  * see flexcop.c for copyright information
6  */
7 #include "flexcop.h"
8 
9 #if 0
10 /*EEPROM (Skystar2 has one "24LC08B" chip on board) */
11 static int eeprom_write(struct adapter *adapter, u16 addr, u8 *buf, u16 len)
12 {
13 	return flex_i2c_write(adapter, 0x20000000, 0x50, addr, buf, len);
14 }
15 
16 static int eeprom_lrc_write(struct adapter *adapter, u32 addr,
17 		u32 len, u8 *wbuf, u8 *rbuf, int retries)
18 {
19 int i;
20 
21 for (i = 0; i < retries; i++) {
22 	if (eeprom_write(adapter, addr, wbuf, len) == len) {
23 		if (eeprom_lrc_read(adapter, addr, len, rbuf, retries) == 1)
24 			return 1;
25 		}
26 	}
27 	return 0;
28 }
29 
30 /* These functions could be used to unlock SkyStar2 cards. */
31 
32 static int eeprom_writeKey(struct adapter *adapter, u8 *key, u32 len)
33 {
34 	u8 rbuf[20];
35 	u8 wbuf[20];
36 
37 	if (len != 16)
38 		return 0;
39 
40 	memcpy(wbuf, key, len);
41 	wbuf[16] = 0;
42 	wbuf[17] = 0;
43 	wbuf[18] = 0;
44 	wbuf[19] = calc_lrc(wbuf, 19);
45 	return eeprom_lrc_write(adapter, 0x3e4, 20, wbuf, rbuf, 4);
46 }
47 
48 static int eeprom_readKey(struct adapter *adapter, u8 *key, u32 len)
49 {
50 	u8 buf[20];
51 
52 	if (len != 16)
53 		return 0;
54 
55 	if (eeprom_lrc_read(adapter, 0x3e4, 20, buf, 4) == 0)
56 		return 0;
57 
58 	memcpy(key, buf, len);
59 	return 1;
60 }
61 
62 static char eeprom_set_mac_addr(struct adapter *adapter, char type, u8 *mac)
63 {
64 	u8 tmp[8];
65 
66 	if (type != 0) {
67 		tmp[0] = mac[0];
68 		tmp[1] = mac[1];
69 		tmp[2] = mac[2];
70 		tmp[3] = mac[5];
71 		tmp[4] = mac[6];
72 		tmp[5] = mac[7];
73 	} else {
74 		tmp[0] = mac[0];
75 		tmp[1] = mac[1];
76 		tmp[2] = mac[2];
77 		tmp[3] = mac[3];
78 		tmp[4] = mac[4];
79 		tmp[5] = mac[5];
80 	}
81 
82 	tmp[6] = 0;
83 	tmp[7] = calc_lrc(tmp, 7);
84 
85 	if (eeprom_write(adapter, 0x3f8, tmp, 8) == 8)
86 		return 1;
87 	return 0;
88 }
89 
90 static int flexcop_eeprom_read(struct flexcop_device *fc,
91 		u16 addr, u8 *buf, u16 len)
92 {
93 	return fc->i2c_request(fc,FC_READ,FC_I2C_PORT_EEPROM,0x50,addr,buf,len);
94 }
95 
96 #endif
97 
calc_lrc(u8 * buf,int len)98 static u8 calc_lrc(u8 *buf, int len)
99 {
100 	int i;
101 	u8 sum = 0;
102 	for (i = 0; i < len; i++)
103 		sum = sum ^ buf[i];
104 	return sum;
105 }
106 
flexcop_eeprom_request(struct flexcop_device * fc,flexcop_access_op_t op,u16 addr,u8 * buf,u16 len,int retries)107 static int flexcop_eeprom_request(struct flexcop_device *fc,
108 	flexcop_access_op_t op, u16 addr, u8 *buf, u16 len, int retries)
109 {
110 	int i,ret = 0;
111 	u8 chipaddr =  0x50 | ((addr >> 8) & 3);
112 	for (i = 0; i < retries; i++) {
113 		ret = fc->i2c_request(&fc->fc_i2c_adap[1], op, chipaddr,
114 			addr & 0xff, buf, len);
115 		if (ret == 0)
116 			break;
117 	}
118 	return ret;
119 }
120 
flexcop_eeprom_lrc_read(struct flexcop_device * fc,u16 addr,u8 * buf,u16 len,int retries)121 static int flexcop_eeprom_lrc_read(struct flexcop_device *fc, u16 addr,
122 		u8 *buf, u16 len, int retries)
123 {
124 	int ret = flexcop_eeprom_request(fc, FC_READ, addr, buf, len, retries);
125 	if (ret == 0)
126 		if (calc_lrc(buf, len - 1) != buf[len - 1])
127 			ret = -EINVAL;
128 	return ret;
129 }
130 
131 /* JJ's comment about extended == 1: it is not presently used anywhere but was
132  * added to the low-level functions for possible support of EUI64 */
flexcop_eeprom_check_mac_addr(struct flexcop_device * fc,int extended)133 int flexcop_eeprom_check_mac_addr(struct flexcop_device *fc, int extended)
134 {
135 	u8 buf[8];
136 	int ret = 0;
137 
138 	if ((ret = flexcop_eeprom_lrc_read(fc,0x3f8,buf,8,4)) == 0) {
139 		if (extended != 0) {
140 			err("TODO: extended (EUI64) MAC addresses aren't completely supported yet");
141 			ret = -EINVAL;
142 		} else
143 			memcpy(fc->dvb_adapter.proposed_mac,buf,6);
144 	}
145 	return ret;
146 }
147 EXPORT_SYMBOL(flexcop_eeprom_check_mac_addr);
148